This is one of the longest possible 747 flights. Looking at some of the flightaware data for them it appears they operate beyond the published range for the aircraft. According to Boeing, the range for a Boeing 747-400 is listed as 7260nm (8354sm).
QFA8 DFW-BNE is planned at 8713sm. Yesterday's run flew 8561sm, the day before flew 8357sm.
QFA7 SYD-DFW is enroute now, planned at 8585sm. In fact, the last 5 days of QFA7 have all been 8500-8800sm.
Are all of these flights flown with weight restrictions, allowing them to carry more fuel for more range? Of course there is a maximum limit of how much fuel can fit in the tanks, I wonder how much they carry? Does Qantas operate this flight with standard seating configuration or some reduced passenger setup (like all biz class)? And if they have to go out weight restricted every day how can this route be profitable? I'm intrigued at how they can operate this with a normal B744 on a daily basis.